#include <cstdio>

#include <cstring>

#include <cstdlib>

#include <cmath>

#include <set>

#include <map>

#include <string>

#include <algorithm>

#include <vector>

#include <iostream>

#include <queue>

using namespace std;

#define ll long long

#define F(i,j,k) for (int i=j;i<=k;++i)

#define D(i,j,k) for (int i=j;i>=k;--i)

#define maxn 20005

#define mlog 20

#define mxle 64

#define mxed 50005

int Getint()

{

    int x=0,f=1; char ch=getchar();

    while (ch<'0'||ch>'9') {if (ch=='-') f=-1; ch=getchar();}

    while (ch>='0'&&ch<='9') {x=x*10+ch-'0'; ch=getchar();}

    return x*f;

}

ll Getll()

{

    ll x=0,f=1; char ch=getchar();

    while (ch<'0'||ch>'9') {if (ch=='-') f=-1; ch=getchar();}

    while (ch>='0'&&ch<='9') {x=x*10+ch-'0'; ch=getchar();}

    return x*f;

}

void Finout()

{

    #ifndef ONLINE_JUDGE

    freopen("in.txt","r",stdin);

    #endif

}

struct Base{

	ll lb[mxle];

	void add(ll x)

	{

		D(i,63,0)

		{

			if ((x>>i)&1)

			{

				if (!lb[i]) {lb[i]=x;break;}

				else x^=lb[i];

			}

		}

	}

	void init(ll x){memset(lb,0,sizeof lb);add(x);}

};

Base add(Base x,Base y)

{

	Base ret=x;

	F(i,0,63) if (y.lb[i]) ret.add(y.lb[i]);

	return ret;

}

int f[maxn][mlog],n,q,h[mxed],to[mxed],ne[mxed],en=0,dst[maxn];

Base g[maxn][mlog];

void add(int a,int b)

{

	to[en]=b; ne[en]=h[a]; h[a]=en++;

	to[en]=a; ne[en]=h[b]; h[b]=en++;

}

void dfs(int o)

{

	for (int i=h[o];i>=0;i=ne[i])

		if (f[o][0]!=to[i])

		{

			f[to[i]][0]=o;

			dst[to[i]]=dst[o]+1;

			dfs(to[i]);

		}

}

ll query(Base x)

{

	ll sum=0;

	D(i,63,0)

	if ((x.lb[i]^sum)>sum) sum^=x.lb[i];

	return sum;

}

ll ask(int a,int b)

{

	if (dst[a]<dst[b]) swap(a,b);

	Base ret;ret.init(0);

	int dist=dst[a]-dst[b];

	D(i,mlog-1,0)

		if ((dist>>i)&1)

		{

			ret=add(ret,g[a][i]);

			a=f[a][i];

		}

	if (a==b)

	{

		ret=add(ret,g[a][0]);

		return query(ret);

	}

	D(i,mlog-1,0)

		if (f[a][i]!=f[b][i])

		{

			ret=add(ret,g[a][i]);

			ret=add(ret,g[b][i]);

			a=f[a][i];b=f[b][i];

		}

	ret=add(ret,g[a][1]);

	ret=add(ret,g[b][0]);

	return query(ret);

}

int main()

{

	Finout();

	memset(h,-1,sizeof h);

	n=Getint(); q=Getint();

	F(i,1,n) g[i][0].init(Getll());

	F(i,1,n-1) add(Getint(),Getint());

	dfs(1);

	F(i,1,mlog-1)

		F(j,1,n)

		{

			f[j][i]=f[f[j][i-1]][i-1];

			g[j][i]=add(g[j][i-1],g[f[j][i-1]][i-1]);

		}

	F(i,1,q) printf("%lld\n",ask(Getint(),Getint()));

}